The sum of squared intraday returns provides an unbiased and almost error-free measure of ex-post volatility. In this paper we develop a nonlinear Autoregressive Fractionally Integrated Moving Average (ARFIMA) model for realized volatility, which accommodates level shifts, day-of-the-week...

The sum of squared intraday returns provides an unbiased and almost error-free measure of ex-post volatility. In this paper we develop a nonlinear Autoregressive Fractionally Integrated Moving Average (ARFIMA) model for realized volatility, which accommodates level shifts, day-of-the-week...

We introduce a heuristic bias-adjustment for the transaction price-based realized range estimator of daily volatility in the presence of bid-ask bounce and non-trading. The adjustment is an extension of the estimator proposed in Christensen et al. (2009). We relax the assumption that all...

Persistence in mutual fund performance is usually measured by the risk-adjusted returns of the portfolio that is long the top and short the bottom past year return deciles. A key challenge is to properly adjust for the time-varying risk exposures of this portfolio. We show that the Fama and...

We find increasingly large variations in returns from momentum strategies in recent years. Momentum strategies did not earn significant excess returns during the period of 1993-2004 which was due to their poor performance over the period from 2001-2004. Using sub-samples of smaller...